On Wednesday, Chief of Naval Operations Adm. Jonathan Greenert unveiled the Navy’s plan to integrate female soldiers into its submarine force.

Female officers were first invited to serve on submarines in 2010, but the amount of submarine positions open to women remain limited. In the Navy’s new plan, female enlisted sailors will be gradually integrated into different submarine crews. Women will first be stationed on Ohio-class ballistic-missile submarines. By 2016, the Navy is to station women aboard the guided-missile submarine USS Michigan. By 2021, women will be integrated into 12 additional crews over a five year period.

While this plan has been in development for some time, it was rocked by scandal in December when a dozen sailors were investigated for secretly recorded female soldiers aboard the USS Wyoming. The investigation of this incident is ongoing.